Stock feeding mechanism



Aug. 30, 1949. F. H. B GART 2,480,700

STOCK FEEDIIEG MECHANISM Original Filed Feb. 21, 1942 2 Sheets-Sheet l IINVENTOR. FPEp H. Boa/m7- ATTORNEY-5 1949- I F. H. BOGART 2,480,700

STOCK FEEDING MECHANISM Original Filed Feb. 21, 1942 2-Shets-Sheec 2 AORNE Patented Aug. 30, 1949 STOCK FEEDING MECHANISM Fred H. Bogart,South Euclid, Ohio, assignor to The Warner & Swasey Company, Cleveland,Ohio, a corporation of Ohio Original application February 21, 1942,Serial No.

431,809, new Patent No. 2,388,594, dated Novemher 6, 1945. Divided andthis application September 29, 1943, Serial No. 504,205

Claims.

This invention relates to a machine tool and particularly to the stockfeeding and gripping mechanism thereof. 7

This application is a division of my application Serial No. 431,809,filed February 21, 1942, now Patent No. 2,388,594, granted November 6,1945.

The principal object of the invention is to provide an improved stockfeeding and gripping mechanism for a machine tool.

Another object is to provide an improved stock feeding and grippingmechanism for a machine tool wherein the parts are soformed and arrangedas to perform their operative functions in the correct sequence andwithin predetermined time periods, thus increasing the efficiency of themechanism.

Another object is to provide an improved stock feeding mechanism for amachine tool.

A still further object is to provide an improved stock feeding mechanismfor a machine tool which functions to feed the stock uniformly inpredetermined lengths, thus obviating the necessity, in many instances,of using stock stops.

A still further object is to provide an improved stock feeding andgripping mechanism which functions to grip and centralize the stock at apoint outwardly of the stock feeding portion of the mechanism to preventslipping thereof and which acts to maintain the stock against endwisemovement under machining operations as well as holding the stock againstwhipping action while rotating.

Further and additional objects and advantages not specifically referredto above will become apparent during the detailed description of anembodiment of the invention which will be set forth hereinafter.

Referring to the accompanying drawings,

Fig. 1 is a front view, partly in elevation and partly in section, of astock feeding and gripping mechanism.

Fig. 2 is a view, partly in elevation and partly in section, of thestock gripping and feeding means shown in Fig. 1 and on a larger scale.

Fig. 3 is a top plan view of the stock gripping and feeding means shownin Fig. 2 and with the parts thereof in different relationship.

Fig. 4.- is a sectional view taken on irregular line 4-4 of Fig. 2,looking in the direction of the arrows.

2 Fig. 5 is a detail sectional view taken substan tially along line 5-5of Fig. 2, looking in the direction of the arrows, and

Figs. 6 and 7 are detail sectional views taken respectivelysubstantially along lines 6-8 and i--'l of Fig. 3, looking in thedirection of the arrows.

It will be understood that the stock feeding and gripping mechanismembodying the present invention is shown by way of illustration asfunctioning in conjunction with a work spindle which extends into and issupported by the headstock of a machine tool, as is well known in theart and therefore said headstock has not been illustrated herein. Itwill be understood also that the housing which supports the stockfeeding and gripping mechanism is secured by suitable means to the endof such headstock.

Referring to Fig. 1, the housing is indicated at l0, while the workspindle is shown at El Ii. The spindle is shown as provided with acollet of the push-out type and having spring jaws I2 which haveinclined arcuate surfaces cooperating with similarly inclined annularsurfaces on the collet hood 13 which is screwed onto the end of the workspindle l I. It will be understood that movement of the collet towardthe right, as viewed in Fig. 1, will cause the jaws to be cammedradially inwardly to grip the work It. Slidably supported in the bore ofthe work spindle H is a collet sleeve l5 which has its right hand endabutting the collet while its left hand end projects beyond the workspindle outside the headstock and is provided with an annular shoulderit. A finger housing 9? is mounted adjustably on the work spindle If andthis finger housing has pivotally mounted therein fingers it in the formof bell crank levers. The fingers it are provided with heel portions l9contacting the annular shoulder l6 of the collet sleeve. The fingersalso are provided with rollers carried by the ends of the long arms ofthe levers and engageab-le with the periphery of a cone as that isslidably mounted on the work spindle and has an annular groove formedtherein in which are located rollers carried by lever arms Ed whichstraddle the cone as fully explained in said copending applicationSerial No. 431,809, of which the present application is a division, one01' said lever arms being shown in Fig. 1. It will be unas viewed in thedrawings.

derstood that when said lever arms are rocked to move said cone towardthe left, as viewed in Fig. 1, the fingers is will be spread to causethe heel portions l9 to press against the annular shoulder it of thecollet sleeve and move the sleeve and collet toward the right, whereuponthe collet jaws 12 are cammed inwardly by the collet hood 13 to stockgripping position. Conversely, when the lever arms are rocked in theopposite direction to move the cone toward the right the outwardpressure on the fingers I8 is relieved, whereupon the collet sleeve andcollet move toward the left under the action of the spring jaws and thegripping of said jaws on the work is relieved. The mechanism by whichthe lever arms 20 are rocked to efiect the gripping and releasingmovements of the collet is fully illustrated and described in saidcopending application Serial No. 431,809 and need not be set forthherein.

The mechanism last referredto is operated by an electric motor 2|andiscontrolled-zbyulever 22. The mechanism which operates thelever arms20* to cause the gripping and releasing; of

the collet also actuate's a lever arm 23 as fully explained in saidcopendingapplication Ser. No. 431,809; This lever arm 23 is providedwith a T-slot extending longitudinally of the arm and in which a shoe 24is mounted for adjustment lengthwise of the slot by means of anadjusting The shoe 24 is-pivotally connected central openingtherethrough and rotatably supporting therein'by means of antifrictionbearings 29 carriedby'theiportion 28a sleeve 30 which at its right handend is provided with an The slide 21 s has an upstanding portion 28provided with a Lil 4 right as viewed in Fig. 2 and is provided withelongated slots 3'1 through which slots extend shouldered screws 38 thatare threadedly engaged with a slidable support 39. The support 39 has anupstanding portion 4|] provided with a central opening and rotatablysupporting in said opening by means of antifriction bearings 4| a sleeve42 which is provided at its inner end with an outstanding flange 43contacting the left hand side of the upstanding portion 40 of thesupport 39. The sleeve 42 can rotate freely in the portion 40 but willmove endwise with said portion and with the support 39 due to theengagement of the flange 43 with the portion 40 and to the engagement ofa lock washer 44 for the antifriction bearings 41 with a groove in thesleeve 42 and in the portion 40. The flange 43'of the sleeve 42 isprovided with radially extending openings arranged diametrically to eachother and slidably receiving radially adjustable jaw carriers later tobe referred to. A plate 45 is securedjso the left hand face of theflange 43 and outstanding flange 3| that engages in a recess" formed inthe right hand face of theportion 28. It will be seen that movementofthe slide '2'! and portion 28' toward the right as viewed in thedrawings will cause a corresponding movem'ent of the sleeve 30.- 1

The antifriction bearings 29- are held in position by a suitable lockwasher 32, well known in the art, and which lock washer engages in arecess formed in-the -sleeve 3ll; wherefore endillustration andthey arearranged diametrically with respect to each other, although it will beunderstood that a greater or lesser number of T- slots could be employedif desired. The T.-slots 33 adjustably guide and support the heads ofwedge members 34;which members project perpendicularly from the flange 3I toward the right The heads of the wedge members 34 can be adjustedinthe-T-slots 33 to varying radial distances from the center of thesleeve 30, while the wedge members will move ways; The front gib 36-;isextended toward the has an integral sleeve portion 46 telescopicallyextending into the sleeve 30.

It will be understood that the plate 45 and sleeve'portionlfi could beintegral with the sleeve -'42ahd the flange 43 but for the purposes ofmanufacture and assembly the plate and its sleeve portion are made as aseparate element detachably connected to the flange 43. The plate 45 isprovided with radially extending openings 41 substantially of the widthof the wedge members 34 and which members slidably pass through theopenings 4'! and into the radially extending openings formed in theflange 43.

' Itv will be seen that the sleeve 42, flange 43, plate 45 and itssleeve portion 46 can move endwise relativeto the sleeve 30 but willrotate with said sleeve 30 since the wedge members 34 in the openings 47act as keys for thisrotative movement v As previously referred to, theradial openings in the flange 43 movably support jaw carriers 48.Although Fig. 4 actually shows the construction of the stationarysupport that is to the left of the slide 21 in Fig. 2, reference may bemade to said Fig. 4 in connection with the description of theslidablesupport 39 that is at the right of the slide 21 since bothsupports include similar elements designated by the same referencecharacters. 1

Thecarrierss48 are provided with openings through which-the wedgemembers 34 project. The carriers 48 above the wedge members 34 supportrollers 49 in contact with the upper straight side of the wedge members34.- The carriers .48 slidably support beneath the wedge members 34radially movable 'jaws 50 which carry'rollers 5| that contact the'incllnedfsurface-of the wedge members 34'. '-'The jaWs'5O are adaptedto engage and grip the work or bar stock l4 when they aremovedradiallyinwardly relative to the carriers by the wedging acticn'of thewedge members34.

The carriers 48 are radially adjustable with an equalizedmovement fordifferent diameter stock 'by themeans now to be explained. The carrierson one side thereof are provided with -threaded -portions 52 engagingwith right and left handed-screw'portions 53 formed on a shaft extendinthrough'the flange 43'and along side and parallel with the jaw carriers48. The shaft withthescrew portions 53canberotated by means of asuitable wrench fitting inrthe socket $4 at the upper end of the shaft.and accessible from the upper side of the flange 43.

It will be understood that rotation of the shaft effects equalizedinward or outward movement of the carriers 48 to approximately adjustthe jaws 50 for different diameter stock. The shaft can be lockedagainst rotation after it has been rotated for adjustment by means of alock screw 55 mounted in the flange 43.

At the rear of the slidable support 39 an elongated flat friction plate56 is located between the depending portion of the support and the rearsurface of the rear way on the extension of the housing is. The plate 56is connected to the support 39 to move therewith by pins ,5], see Figs.3 and 7. The depending portion at the rear of the support 39 is providedwith a plurality of threaded openings spaced longitudinally of thesupport and in which are mounted coil springs 58 held in position bythreaded plugs screwed into the openings, see Figs. 3 and 6. It will beseen that the springs 58 exert pressure on the plate 56 and cause thesame to frictionally engage with the rear surface of the rear way on thehousing It thus producing a friction drag to the movement of the support39 for a purpose later to be explain-ed.

At the left of the sleeve 39 is a flange 69 which has an integralelongated sleeve portion 6! tele scoping within the sleeve portion 46and within the sleeve 30 of the flange 3|. The sleeve 39 isprovidedinternally and at its left hand end as viewed in the drawingwith a circumferential groove 62 formed by an internal rib in the sleeve36 and by an inwardly extending flange at the left hand end of saidsleeve, see Figs. 2 and 5. A spring 63 is mounted in the groove 62 andsaid spring at alternate circumferentially spaced points contacts theinterior of the sleeve 36 and the exterior of the sleeve 6|, thereforeproducing a frictional drag to relative telescopic movement between thesaid sleeves.

The flange 60 is identical with the flange 3! in that it is providedwith a plurality of radially extending T-slots 33 which adjustablysupport the heads of a plurality of radially movable wedge members 34. Anormally stationary support 64 is mounted on the ways of the extensionof the housing Iii for adjustment thereon and said support can beclamped and locked in adjusted position against endwise movement on saidways by a clamp 65 and a lock screw 66. The stationary support 64 has anupstanding portion 5'! which is provided with a circular opening inalignment with the opening in the portion 28 of the slide 21 and alsowith the similar opening in the portion id of the slidable support 39.The portion 61 is substantially the same as the portion 40, except thatit is of greater width and can accommodate a pair of antifrictionbearings 68.

The work gripping means carried by'the portion 57 of the stationarysupport 64 is identical with the work gripping means carried by theportion 46 of the slidable support 39 and the parts thereof have beengiven the same reference characters. As already explained, the workgripping means comprises a sleeve 42 which is provided with anoutstanding flange 63 contacting in this instance the right hand side ofthe portion 61 of the stationary support 64. The sleeve 42 rotatesfreely in the upstanding portion 61 but is held against endwise movementrelative to said portion by the flange 43 and by the engagement of thelock washer 44 for the antifriction bearings 68 with a groove in thesleeve 42 as will be well understood. 5

As already explained, the flange 43 of the sleeve 42 is provided withradially extending openings arranged diametrically to each other andslidably receiving radially adjustable jaw carriers 48. A plate 69 issecured to the right hand face of the flange 43 and corresponds to theplate 65 but is not provided with an integral sleeve portion. The plate69 is provided with radially extending openings 10 corresponding to theopenings M in the plate 45 and substantially of the Width of the wedgemembers 34, so that said wedge members can slidably pass through theopenings 10 and into the radially extending openings formed in theflange 43. The plate 69 is also provided with openings through whichextend headed stop screws ll which are screwed into the flange fill andhave their heads to the left .of the plate 89. The purpose of the screwsH is to limit relative movement between the flange 6t and the plate 69,see Fig. 3.

It will be seen that the sleeve i2, flange 43 and plate 69 will rotatewith the flange 59 since the wedge members 36 act as keys. It will alsobe seen, however, that the wedge members 34 can move endwise relative tothe plate 69 and the flange d3. It will further be seen that the wedgemembers 3 3 can move radially of the flange 80 and the flange 43 in theopenings it when the jaw carriers i8 are adjusted radially.

As already explained, the carriers 48 are provided with openings throughwhich the wedge members 3 project. The carriers 48 above the wedgemembers 34 support rollers 49 in contact with the upper straight side ofthe wedge members 3 iand beneath the wedge members the carriers slidablymount radially movable work gripping jaws 58 which carry rollers 5| thatcontact the inclined lower surfaces of the wedge members 34. The jaws 50are adapted to engage and grip the work-or bar stock It when the jawsare moved radially inwardly by the wedging action of the wedge members34. The carriers 48 can be adjusted radially inwardly and outwardly fordifferent diameter work by the shaft having the right and left handscrew portions 53 as has already been explained.

The operation of the stock feeding and gripping mechanism disclosed andheretofore described will now be explained. It will be understood thatthe work gripping mechanism in the form of the collet l2 and theactuating means for imparting the work feeding movement and restoringmovement to the slide 21 function in the manner described in detail insaid copending application Serial No. 431,809, of which the presentapplication is a division. In Fig. 1 the collet jaws 12 are gripping thework. At this time the work gripping jaws 59 carried by the stationarysupport 54 are also gripping the work Hi, since the wedge members 34carried by the flange 60 are in wedging position, see Fig. 2. Also atthis time the slide 2? is in the position it occupies before the workfeeding movement is imparted thereto.

Assuming that the operator has moved the control handle 22 to effect arelease of the gripping action of the collet jaws on the work and thefeeding of a length of the stock for a new work piece, it will beunderstood that the movement of the link 25 causes the slide 27 to startmoving toward the right, as viewed in Fig. 2. The very first part ofthis movement of the slide 2'! toward the right accomplishes two thingssimultaneously; one of these things is that as the.

portion 28 of the slide 21 moves toward the right it carries with it theflange 3i and the sleeve 30 :anclforces the wedge members, carried bysaid :flange 3| endwise toward the rightwbetween the rollers, and, 5|to. move thework gripping jaws 59 of. the slidable support 39 intogripping relation with the, work M, the slidable support 39beingfrictionally held against movement at this time as will later bereferredto. This movement of the sleeve 39 with the slide 21 also effectsmovement toward the right of the sleeve BI and the flange 69 due, to thefrictional ,grip of the spring 63 on the sleeve -B|., The movement ofthe sleeve BI and flange -60 moves the wedge members 34 carried by saidflange-toward the right and relievesthe gripping pressure upon the workof the jaws 59 that are associated with the stationary support 674.,

The initial portion of the movement of the slide 21 toward the rightdoes not move the slid- ;able support 39, since the latter is held inposition by the friction plate 36 and also because there is a lostmotion connection between front 91b 36 and the screws 38 by virtue ofthe slots 31. Consequently, the movement toward the right of the wedges34 carried by the flange 3| results in radially moving the jaws 59associated with the slidable support 39 into work gripping position.The-continued movement toward the right of the slide 21 after the jaws50 have gripped the work overcomes the resistance of the friction plate56 and causes the slidable support 39 and thejaws carried thereby tomove toward the right as a unit with the slide 21. v This unitarymovement of the slide 21 and slidable support 39 effects a feedingmovement toward the right of the stock l4. During this feeding movementthe slide 39 moves relative to the sleeve 6! since the heads of the stopscrews ll carried by the flange 60 have already engaged with the innerside of the plate -59, see Fig. 3. During the feeding movement justreferred to the friction plate 56 constantly exerts a drag to themovement of the slidable support 39 and consequently the wedge members34 act continuously to urge the jaws 59 into tighter work grippingrelationship. The feeding movement of the slide 21 therefore impartsmovement toward the right of the movable support 39 and the work I4, itbeing observed that the slots 31 are of such length the screws 38 do notcontact with the ends of the slots during the feeding movement and thatthe wedges form the actuating connection between the slide and .themovable support 39. At the end of the feeding movement the parts areinthe position'shown in Fig. 3.

As previously stated, the amplitude of movement toward the right Of theslide 21 can be accurately controlled by adjusting the screw 25 to varythe position of the shoe 24. The first part of this movement of theslide effects a positive gripping of the stock by the jaws 59 of theslidable support while the remainder of the movement effects a definitelength of feed to the stock, thus obviating the need of using stockstops to determine the length of feed.

Assuming that the collet jaws.|2 have again gripped the stock and thelink 26 moves ina direction to restore the slide 21 to its originalposition the following sequence of operations occurs. The first part ofthe movement of the slide 21 toward the left effects no movement of theslidable support 39, due to the lost motion connection and to the gripof the friction plate 56. However, the first part of the restoring ofthe slide 21 moves the wedge members 34 carried by the flange 3! in aleft hand direction to relieve 8 the gripping pressure ontheeworka ofcth'j w associatedwith the slidable support 39.1Simultaneously with therelieving of the grip ing pressures of the jaws 59 just referred to,;thesleeve 6| moves toward the left along withthe Sleeve 39 due to thefriction grip of the sprin 63 and consequently the wedge members 34carried by the flange )6!) move toward the left and force into grippingrelationship with the, work l4 the jaws. 50 associated with thestationary support 84. At this time the screws 38 come into.contactfwith the right hand ends of the slots 31 in the front gib 36,with the result that continued movement of the slide 21 toward the leftmoves the slidable support 39 also toward the left. This continuedmovement of the slide 21 toward the left causes the sleeve 30 to movetoward the left over the sleeve 6|, but due to the frictional grip ofthe spring 63 on the sleeve 6| the latter is constantly urged toward theleft and the wedge members 34' carried by the flange constantly urge thejaws 59 of the stationary support 54 into holding andgrippingrelationship with the work l4 during the machining operation anduntil the parts again function to feed the stock. The flange to does notcome into contact with the plate 69 during this movement toward theleft, it being understood that the heads of the screws H move toward theleft away from the left hand face of the plate 69. .In other words, themovement of the flange 69 and the sleeve 6| toward the left is stoppedby the action of the I wedges 34 urging the jaws into grippingrelationship with the work and not by the engagement of the flange 63with the plate 69; Therefore a tight gripping, action of thejaws Soonthe work piece is established and maintained.

It will be appreciated that the jaws 50 associated with the stationarysupport 64 exert their gripping pressure 'on' the work piece-during theentire. period of the machining operation and consequently the work I4is held centrally in a position at a point substantially removed fromthe point at which the collet jaws l2 grip the work and outwardly of thestock feeding portion of the mechanism, wherefore whipping of the barstock or work inwardly of said point is substantially eliminated. Thejaws 50 of the stationary support 64 also assist the collet jaws l2 inholding the work under heavy machining operations and act to prevent anyendwise movement of the work.

Of course the stock feedingand gripping mechanism described herein maybe employed to hold and feed various kinds'of stock and independently ofany stock gripping means such as the collet shown or other. Well knownforms of stock gripping means such as might be employed in the Workspindle of a turret lathe.

Although a preferred embodiment of the invention has been illustratedand described herein it will be understood that the invention issusceptible of various modifications and changes Within the scope of theappended claims.

Having thus described my invention, I claim:

1. A stock feeding mechanism comprising a movable stock feeding supportand a stationary support each provided with stock gripping means,movable means intermediate said supports and provided with elementscertain of which elements actuate the stock gripping means of themovable support and then act as a driving connection between saidmovable means and said support to cause said support to move with saidmovable means when saidmovable means; is movedin one direction andothers of which actuate the stock gripping means of the stationarysupport when said movable means is moved in the opposite direction.

2. In a stock feeding mechanism, a, movable stock feeding support and astationary support spaced therefrom and each provided with stockgripping means, and movable means intermediate said supports and havinga lost motion operative connection with said movable stock feedingsupport and including telescoping sections having a frictional operativeconnection therebetween, each of said sections being provided withelements, the elements of said sections acting alternately to actuate orrelease the stock gripping means of their cooperating support dependingupon the direction of movement of said movable means, said elementswhich actuate the stock gripping means of the movable support thenacting as a drivingconnection to cause unitary movement of said movablesupport and said movable means.

3. In a stock feeding mechanism, a movable stock feeding support and astationary support spaced therefrom and each provided with stockgripping means and means for adjusting the latter for various sizes ofstock, and means intermediate said supports and movable relative theretoand provided with elements adjustable automatically with the adjustmentof the stock gripping means for actuating or releasing the stockgripping means of one or the other of the supports depending upon thedirection of movement of said movable means, said elements which actuatethe stock gripping means of the stock feeding support then acting as adriving connection to cause unitary movement of said support and saidmovable means.

4. A stock feeding mechanism comprising a movable stock feeding supportand a stationary support each provided with stock gripping means, andmeans intermediate said supports and movable relative thereto andprovided with elements for actuating one or the other of said stockgripping means depending upon the direction of movement of said lastnamed means, certain of said elements being adjacent to the movablesupport and other of said elements being adjacent to the stationarysupport, said elements which are adjacent to the movable support actingas a driving connection between said means and said movable support tocause the same to move in unison after the same elements have actuatedthe stock gripping means of said movable support.

5. In a stock feeding mechanism, a pair of supports one of which ismovable and acts as a stock feeding support and the other of which isstationary and each provided with stock gripping means, and movablemeans intermediate said supports and operatively associated therewithand including relatively movable sections each of which sections isprovided with actuating elements, the elements of one of said sectionsacting to actuate and release the stock gripping means of the stationarysupport while the elements of another of said sections actsimultaneously to actuate and reiease the stock gripping means of themovable stock feeding support depending upon the direction of movementof said movable means, said elements which actuate the stock grippingmeans of the stock feeding support then acting as a driving connectionto cause unitary movement of said stock feeding support and said movablemeans.

FRED I-I. BOGART.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 143,306 Spencer Sept. 30, 1873332,889 Gerry Dec. 22, 1885 755,322 Smith Mar. 22, 1904 1,636,406 BrarenJuly 19, 1927 2,249,325 Pruckner July 15, 1941 2,261,380 Jelinek et al.Nov. 4, 1941 2,343,914 Lloyd Mar. 14, 1944 FOREIGN PATENTS NumberCountry Date 486,091 Great Britain May 27, 1938 107,956 Australia July11, 1939

